Wastewater recovery from laundry operations has become a developed area of industry as water costs increase and the costs of municipality water treatment increases. The advantages of recovery of the wastewater from the laundering process are both economic and environmentally responsible. The user reduces the net demands on the valuable commodity of drinking water, reduces the requirements for sewer disposal, recovers the heat from the wastewater stream and can recover some of the chemicals used in the washing process. Indirect advantages can include decreased demand on equipment needed to provide water heating needs as well as water softening needs in laundry environments. This can extend the life of the equipment, reduce maintenance costs, and in situations where the operation is new, reduce the capacity needs of this equipment, reducing capital expenditures in this area.
In recent years, attention has been focused on methods to recover wastewater from industrial applications. Particular attention has been focused on the wastewater from commercial laundries. Typical commercial laundries use extremely high amounts of water to complete the laundering process. Other systems use methods to recover portions of the rinse water and reuse it for the wash cycle. Other art has focused on methods to capture all the wastewater from the washing machines and use a process of nano-filtration or reverse osmosis filtration to produce adequate water for reuse.
A deficiency of both of these systems is the net percentage of wastewater the processes can hope to recover. Through the recovery of the rinse water only, a system can recycle, at best, 25% of the total water used in the laundering process. In addition, this recovery method is not used for continuous batch style washers due to the fact that the rinse water is never released into the waste stream.
Likewise, a recycle process which employs nano-filtration, reverse osmosis or other type of membrane or ceramic filtration can not exceed about 60% total wastewater recovery due to the filters requirement of continuous flushing. In addition, these types of filtration process can cause additional problems for consumers who have restrictions on the wastewater quality imposed upon them by the local waste water treatment works and the Environmental Protection Agency. These types of filters generally send the flushing water to drain. In these filters concentrate the contaminants in the actual wastewater discharged to drain.